Oil well swab



Sept. 29; 1964 D. H. RILEY on. WELL SWAB Filed Sept. 21. 1962 DAVHD H. RiLEY INVENTOR.

A EN

United States Patent 3,150,607 (BEL WELL SWAB x David H. Riiey, Box 257N, Fox, Okla. Filed Sept. 21, 1962, Ser. No. 225,310 g 2 Claims. (Qt. 1%3-225) The present invention relates to oil well tools and more particularly to an oil well swab.

Conventional oil well swabs are usually run into the c sing of an oil well on a wire line for removing fluids herefrom. Frequently the swab becomes lodged in the -asing by reason of too great a load of fluid thereabove or by sand or other earth formations sanding up the swab and resulting in the necessity of cutting the wire line to release the swab and then removing the latter from the hole by other means which is time consuming and expensive.

It is, therefore, the principal object of the instant invention to provide an oil well swab which may be used in a conventional manner which will release an overload of fluid without material damage to the swab or other equipment.

Another object is to provide a device of this class which utilizes a conventional swab rubber and releasably mounts the latter on the body of the swab by an annular ring surrounding a portion of the body of the swab.

Another object is to provide a device of this class which is easily disassembled for replacing the swab rubber and shear pin.

The present invention accomplishes these and other objects by connecting an annular support ring to the periphery of the swab by a transverse shear pin.

Other objects will be apparent from the following description when taken in conjunction with the accompanying single sheet of drawings, wherein:

The single figure is a vertical cross-sectional view, partly in elevation, of the device.

Like characters of reference designate like parts in those figures of the drawings in which they occur.

In the drawings:

The reference numeral indicates the device, as a whole, comprising an elongated body or mandrel 12 having a threaded upper end portion 14 adapted to be connected to a rope socket, or the like, not shown. Adjacent its upper end, the mandrel 12 is recessed on opposing sides to provide wrench flats 16 for use in connecting the swab to a rope socket. The mandrel 12 is centrally bored, from its lower end, as at 18. Adjacent the upper end of the bore 18, the inner wall of the mandrel is enlarged, as at 20, forming a seat 22 for receiving a ball valve 24. A series of ports 26, through the wall of the mandrel, communicate with the large bore 20.

The depending end portion of the mandrel is diametrically reduced, as at 28, for slidably receiving a conventional swab cup assembly 30. An annular ring 32 surrounds the reduced end portion of the mandrel and is secured thereto by a shear pin 34 extending horizontally through the ring and wall of the mandrel 12. The depending end of the mandrel is threadedly connected to a centrally bored guide or shoe 36. The shoe is characterized by a plurality of longitudinally coextensive vanes which extend radially outward a distance substantially equal to the diameter of the upper end portion of the mandrel thus forming a plurality of fluid courses around the shoe. The wall of the mandrel is provided with a plurality of fluid release ports 38 positioned between the ring 32 and the shoe 36, for the purposes which will be readily apparent.

Operation in operation the device it) is lowered into the casing 40 of an oil well to a point downwardly of the upper level of the fluid. Downward movement of the device through the fluid, not shown, lifts the ball valve 24 ofl its seat 22 and permits fluid to flow upwardly through the bore 18 and out through the ports 26. This fills the casing above the swab and the annulus 42 between the casing 4d and the swab. Upward movement of the device expands the swab cup to form a sliding seal with the inner surface of the casing to pick up fluid positioned above the swab cup. If the device has been lowered to a point in the well wherein the weight of the fluid is greater than the available power for pulling the swab, or, if for any reason the cup assembly becomes lodged or stuck on the inner wall of the casing, upward movement of the mandrel 12 shears the pin or pins 34 which permits the cup assembly 30 to slide downwardly on the mandrel and contact the shoe 36. This permits the fluid within the casing and the annular space around the mandrel above the swab cup to flow inwardly of the mandrel through the ports 38 thereby releasing the fluid load and permitting the entire device to be withdrawn from the well. Thereafter the device may be restored to normal operation by simply replacing the shear pin 34.

Obviously the invention is susceptible to some change or alteration without defeating its practicability, and I therefore do not wish to be confined to the preferred embodiment shown in the drawings and described herein, further than I am limited by the scope of the appended claims.

I claim:

1. A swab, comprising: an elongated vertically disposed mandrel adapted at its upper end to be connected to a wire line and lowered into the casing of an oil well, said mandrel having wrench flats formed on the outer surface of its upper end portion, said mandrel having a diametrically reduced lower end portion and having a central bore extending upwardly from its lower end and terminating downwardly of the lower limit of the wrench flats, said mandrel having an enlarged central bore at the upper end of and communicating with the central bore forming a valve seat on the upper end of the central bore; a ball valve within the enlarged bore for opening and closing said seat, said mandrel having ports in its wall communicating with the enlarged bore above said valve seat and having ports in the wall of its lower end portion; an annular ring surrounding the reduced end portion of said mandrel above the lowermost ports; a shear pin diametrically extended through said ring and said mandrel; and a swab cup assembly surrounding said mandrel and supported by said ring.

2. Structure as specified in claim 1 and a centrally bored guide shoe threadedly connected coaxially to the depending end portion of said mandrel, said shoe having a plurality of longitudinally coextensive vanes extending radially outward a distance substantially equal to the diameter of the upper end portion of said mandrel.

References Cited in the file of this patent UNITED STATES PATENTS 

1. A SWAB, COMPRISING: AN ELONGATED VERTICALLY DISPOSED MANDREL ADAPTED AT ITS UPPER END TO BE CONNECTED TO A WIRE LINE AND LOWERED INTO THE CASING OF AN OIL WELL, SAID MANDREL HAVING WRENCH FLATS FORMED ON THE OUTER SURFACE OF ITS UPPER END PORTION, SAID MANDREL HAVING A DIAMETRICALLY REDUCED LOWER END PORTION AND HAVING A CENTRAL BORE EXTENDING UPWARDLY FROM ITS LOWER END AND TERMINATING DOWNWARDLY OF THE LOWER LIMIT OF THE WRENCH FLATS, SAID MANDREL HAVING AN ENLARGED CENTRAL BORE AT THE UPPER END OF AND COMMUNICATING WITH THE CENTRAL BORE FORMING A VALVE SEAT ON THE UPPER END OF THE CENTRAL BORE; A BALL VALVE WITHIN THE ENLARGED BORE FOR OPENING AND CLOSING SAID SEAT, SAID MANDREL HAVING PORTS IN ITS WALL COMMUNICATING WITH THE ENLARGED BORE ABOVE SAID VALVE SEAT AND HAVING PORTS IN THE WALL OF ITS LOWER END PORTION; AN ANNULAR RING SURROUNDING THE REDUCED END PORTION OF SAID MANDREL ABOVE THE LOWER- 